If引导条件状语从句和宾语从句

  if引导的条件状语从句和的宾语从句中的时态

内容提要: 1. 含有if引导的条件状语从句的复合句中主从句的时态。 2. If引导的宾语从句与条件状语从句的区别。    考情分析:          通常在单项选择、语法选择填空、完形填空等题型中考查。

知能提升:

（一）知识讲解 【认知讲解】 I. if引导的宾语从句 if 引导宾语从句时，意思为：是否，从句的时态通常要和主句保持一致。 【例句】 I want to know if he lives there. 我想知道他是否住在那儿。 He asked me if I could help him. 他问我是否能帮他。 【考查点】if、whether引导的宾语从句的区别

1. if或whether引导宾语从句时，作“是否”讲，常放在动词ask、see、say、know和find out等后面。一般情况下，两者常可换用，在口语中多用if。 【例句】 Nobody knows whether / if it will rain tomorrow.没有人知道明天是否下雨。   Lucy asked whether / if they had a cotton sweater.露西问他们是否有棉制的毛衣。

2. if或whether引导宾语从句时，要注意三个方面，即连词、语序和时态。

if或whether既不能和that 或其他连词（副词）同时使用，也不能省略。 【例句】 我不知道他今天是否会来。 [误] I don’t know that if(whether) he will come here today. [正] I don’t know if(whether) he will come here today.他走过来看看猫是否出了毛病。

[误] He came to see what if (whether) there was anything wrong with his cat . [正] He came to see if (whether) there was anything wrong with his cat .

if或whether引导宾语从句时，虽具有疑问的意义，但其从句应用陈述句的语序。

【例句】 Did you know the way to the hospital?　 The old woman asked me.

The old woman asked me if / whether I knew the way to the hospital.老妇人问我是否知道去医院的路。

if或whether引导的宾语从句应和主句的时态保持一致。即主句为一般现在时，从句用任一种时态；主句为一般过去时，从句则用过去时中的任一种时态。

【例句】 I don’t know if (whether) he has come here.我不知道他是否来过这儿。 Tom asked if (whether) I had read the book.汤姆问我是否看过这本书。

3. 只能用whether的情况:

1) 在动词不定式之前只能用whether： 【例句】 I can’t decide whether to stay.　我不能决定是否留下。 在whether …or not 的固定搭配中： 【例句】 I want to know whether it’s good news or not.我想知道它是不是好消息。

2) 在介词后，只能用whether： 【例句】 His father is worried about whether he loses his work.他的父亲担心他是否会失去工作。

3) 用if会引起歧义时：

【例句】 Could you tell me if you know the answer?

这句话有两种意思： “你能告诉我你是否知道答案吗？” 或 “如果你知道答案，请告诉我，好吗？”。

如用whether则可避免歧义。 【考题链接】 I don’t know _____ they could pass the exam or not. A. why   B. if   C. that   D. whether 答案：D 解题思路：本题考查if与whether的区别，在whether…or not的固定搭配中通常只用whether。

II. if引导的条件状语从句

1. 含义     条件状语从句是在复合句中作条件状语的句子。      表示假如有从句的动作发生就会有主句的动作发生，条件状语从句常由从属连词if引导。 【例句】 You will catch the bus if you get up early.如果你早起的话，就能赶上公共汽车。

2. 类别

1) 主祈从现： 主句是祈使句, 从句是由if引导的使用一般现在时的句子。

【例句】 If you want to go, please tell me. 如果你想去，请告诉我。 Print the photo if you like it. 如果你喜欢这照片就把它打印出来。

2) 主将从现：指if引导的条件状语从句用一般现在时，主句用一般将来时。

【例句】 If it doesn’t rain tomorrow, we’ll go to the Great Wall.如果明天不下雨，我们就会去长城。

If you don’t get up early, you will be late for school.如果你不早点起床，你上学就会迟到。

3. if引导的条件状语从句用法：

（1）位置 if引导的条件状语从句，既可放在主句之前也可放在主句之后。当从句置于主句之前时，常用逗号与主句隔开。 【例句】 You will catch the bus if you get up early. =If you get up early, you will catch the bus.如果你早起的话，就能赶上公共汽车。

（2）时态 应遵循主、从句时态呼应的原则。 当主句是一般现在时（包含祈使句和含情态动词can, may, must等的句子），从句也用一般现在时。 【例句】 You must see the doctor if you are ill. 如果你生病了，你必须去看医生。 　　If you want to go skating, wear warm clothes.如果你想去溜冰，穿上暖和的衣服。

    如果主句是一般将来时，从句必须用一般现在时。 【例句】　　    You will be late for school if you get up late.如果你起晚了，你上学将迟到。 If it rains tomorrow, we won’t go to the Great Wall.如果明天下雨，我们就不去长城了。

（3）在if引导的条件状语从句中，当主句是一般将来时时，不能使用be going to结构，而要用will。 【例句】 　　I’ll help you with your English if I am free tomorrow.如果明天我有空，我会帮助你学英语。

（4）在if引导的条件状语从句中不能使用some，而要用any。

【例句】 If you have any questions to ask, please come to my office.如果你有问题要问的话，请到我办公室来。

（5）同义句转换 　　if引导的条件状语从句可转换成简单句，其方法如下： * 借助“祈使句 and/ or 简单句”结构。其中and表示句意顺承，or表示句意转折。

【例句】 　　If you work hard, you’ll pass the exam. 　　=Work hard, and you’ll pass the exam. 如果你努力学习，你就会通过考试。 　　If you don’t hurry up, you’ll be late. 　　= Hurry up, or you’ll be late. 　　如果你不快点，你将会迟到。

**借助介词with 或without来转换。

【例句】 　　If you help me, I’ll finish my job soon. 　　=With your help, I’ll finish my job soon. 　　如果你帮我，我将很快完成我的工作。 　　If there is no water, fish may die. 　　= Fish may die without water.　如果没有水，鱼可能会死。

另外，if从句还表示不可实现的条件或根本不可能存在的条件，即一种虚拟的条件或假设。从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。

【例句】 If I were you，I would invite him to the party．如果我是你，我会邀请他参加聚会。 I would have arrived much earlier if I had not been caught in the traffic．要不是交通堵塞，我会来得更早一些。

4. 口诀： if 条件句不一般，几个要点记心间； 条件句，放在前，逗号要放句中间。 条件句表可能，主句多用将来时； 条件句表事实，主句常用现在时。

III. If引导的宾语从句和条件状语从句的区别

if引导条件状语从句时意为“如果”，引导宾语从句时意为“是否”，可用whether替换。

【例句】 1) We will go out if it is fine tomorrow. 如果明天天好，我们就出去。 2) I don’t know if the train has arrived. 我不知道火车是否已经到达。

句1)中if引导的是状语从句。这个从句表示“条件”。

句2)中if引导的是宾语从句，充当谓语动词don’t know的宾语。 【考题链接】 I don’t know _________ he will come tomorrow. _________ he comes, I’ll tell you．

A. if; Whether    B. whether; Whether     C. if; That  D. if; If

答案：D 解题思路：第一个空处为宾语从句的引导词，用if、whether都可以；第二个空为条件状语从句的引导词，需用if，综合考虑，D项正确。

（二）提分技巧 1. 熟练掌握if引导的宾语从句与条件状语从句的特点。   2. 熟知if引导的宾语从句与条件状语从句引导词的区别。

（三）即学即练I. 句型转换 1. Do they want fried chicken? He asked the boys.(改为宾语从句)   He asked the boys _______they ______fried chicken.  2. Was the watch made in Shanghai? I don’t know.(改为宾语从句)   I don’t know _______the watch _______made in Shanghai.　　 3. “Do you want to try something new?” Tom’s mother asked him.(同义句转换) Tom’s mother asked him ____________to try something new.

答案： 1. if / whether, wanted   2. if / whether, was   3.  if / whether he wanted

II. 用括号中所给动词的适当形式填空 1. If it _______ (not rain)tomorrow, _______(let) us go shopping. 2. Please _________ (tell)me if you _________ (go). 3. If you ______ (be)ill, you ______ (have)to see the doctor. 4. I _________ (leave)for Beijing if it _______(not snow) this afternoon.

答案： 1. doesn’t rain, let    2. tell, go   3. are, have    4. will leave, doesn’t snow

III. 将下列句子翻译成英语。 1. 如果明天不下雨，我就和同学们去野餐。 _________________________________.

2. 如果周日你去购物的话，我就去。 __________________________________________. 3. 如果你想减肥（lose weight），就锻炼身体吧。 _________________________________________. 4. 如果冬天来了，春天还会远吗？ _____________________________________. 5. 如果可能的话，我就去火车站接你。 _____________________________________.

答案： 1. If it doesn’t rain tomorrow, I will have a picnic with my classmates. 2. I will go shopping on Sunday if you do. 3. Take some exercise if you want to lose weight. 4. If winter comes, can spring be far behind? 5. If (it is) possible, I’ll meet you at the train station.

                                         期中复习（一） 一、预习新知 Module 1-Module 5重点基础知识

二、预习点拨 思考问题一：能否先把这5个模块的重点单词、短语、语法整理一下？ 思考问题二：我们已经学习了哪些语法？哪些还是你比较薄弱的？

（答题时间：45分钟） 一、用所给动词的适当形式填空。                                1. If you ________(feel) tired, you _______________ (have) to have a rest. 2. Where _______ he _________(see) the film if he ________________(have) time? 3. If there __________(be) fewer trees, there _______________(be) more pollution. 4. He _____________(dress) more casually if he ________________(not work) on weekends. 5. If Marcia _____________(live) alone, she ___________________(keep) a pet parrot. 6. Lana ________________(buy) a new dress if the old one ____________(be) out of style. 7. The twins ______________(fight) if they_______________(argue). 8. I ____________(have) a bake sale if I _____________(need) money for education. 9. Peter _____________(send) me a beautiful souvenir if he ________________(tour) Spain. 10. If Mr Green ___________(say) I am hard- working, my parents _________(feel) glad. 11.I ____________(go) to the beach if it________________ (not rain) this week. 12. __________they __________(have) a match if the P.E. teacher _____________(be) busy? 13. He ____(write) a letter to his grandparents if he ____(get) his report card this week. 14. If she ____________(get) up late, she _____________ (not catch) the early bus. 15. Peter ________(major) in English if he ____(pass) the exams in Peking University.

二、完成句子（每空一词）。 1. 如果你要过马路，不要乱跑。 _____ _____ around if you cross the road. 2. 明天如果下雨的话，我们将呆在家里。 We _____ _____ at home if it _____ tomorrow. 3. 如果你能说好英语的话，你就可以容易地与外国人交谈。 If you can _____ English well, you _____ ______ ______ foreigners easily. 4. 如果你对别人好，人们也会对你好。 If you’re nice to people, they _____ _____ _____ to you, too. 5. 如果学生不对考试如此担心的话，他们会更开心的。 If students don’t worry about exams so much, they _____ ______ ______. 6. 他如果电视看太多了，他的父母会不高兴。 If he _________ TV too much, his parents __________ __________ unhappy. 7. 如果我们为他组织生日聚会，大家都会来的。 Everyone ________ ________ if we _____________ a birthday party __________ him. 8. 如果明天不下雨，我会和你一起去公园的。 If it __________ __________ tomorrow, I ______________ go to the park _________ you. 9. 如果他有空，他会帮助你的。 If he ________ _________, he _________ ________ you. 10. 如果Tom考试不及格，他就没有机会上高中了。 Tom _________have the ________to go to the senior high school if he _______ _______ the exams.

三、同义句转换。 1. Study hard, or you won’t pass the exam. If you study hard, you _____ _____ the exam. 2. Take a taxi, and you’ll catch the train. _____ you _____ a taxi, you’ll catch the train. 3. If you go to bed early, you won’t feel tired in the morning. _____ _____ _____ early, _____ you won’t feel tired in the morning. 4. If you don’t work hard, your teacher will probably be angry. ______ _____, _____ your teacher will probably be angry. 5. Breathe deeply for one minute, and you’ll feel relaxed. _____ you ______ deeply for one minute, you _____ _____ relaxed.

四、阅读下面的广告，然后用“if..., ...will...”的句式回答问题。 　　Travel Brochure 　　Cheap Cheap Cheap. Beijing for the weekend. 3D/2N. Book Now. 　　Five Star Hotel—Save 50% 　　Four Star Hotel—Save 40% 　　Three Star Hotel—Save 30% 　　Book before December 31st. Breakfast Included. 　　City Tour 50RMB. Visit the Great Wall 100 RMB. 　　 1. How much will you save if you stay at the Four Star Hotel? ___________________________________ 2. How much will you save if you stay at the Three Star Hotel? 　　___________________________________ 3. What will happen if you book after December 31st? 　　___________________________________ 4. How much will you have to pay if you want to go on the City Tour? 　　___________________________________ 5. How much will you have to pay if you want to visit the Great Wall? 　　___________________________________ 　　 五、单项选择 1. If you _____ to the party, you’ll have a great time. A. will go  B. went  C. go   D. going 2. It will be a long time ____ Peter _____ his work. A. since, has finished   B. after, finishes   C. when, will finish D. before, finishes 3. What will father _____ us from Japan? A. take   B. bring   C. carry   D. make 4. Weifang is famous ______ kites. A. for   B. to   C. on   D. with 5. I ____ her the answer if she ____me. A. can tell, will ask   B. will tell, will ask C. would tell, ask   D. will tell, asks 6. —What are you going to do tomorrow? —We’ll go to the library tomorrow if it ___. A. isn’t rain  B. rain   C. won’t rain  D. doesn’t rain 7. —Do you know when he will come back tomorrow? —Sorry, I don’t know. When he ____ back, I’ll tell you. A. comes  B. will come   C. come   D. may come 8. What will you do if you _____ to the old folk’s home visit? A. go   B. went   C. going   D. will go 9. If I eat ____ food, I’ll be very fat. A. too many   B. many too   C. too much  D. much too 10. I’ll give the book to him if he ___ here next Sunday. A. will come   B. comes   C. is coming    D. came 11. There ____an English film in our school tomorrow. A. is going to have  B. will have   C. is going to be   D. has 12. Could you tell us where ____？   A. will the next Olympic Games held   B. the next Olympic Games will be held   C. would the next Olympic Games be held   D. the next Olympic Games would be held 13. When my mother returned last night, I ____a book.   A. read   B. am reading   C. was reading  D. am going to read 14. What ____ you ____ when it began to rain?   A. do, do  B. were, doing  C. are, doing  D. did, do 15. I’ll wake you up when he ____back.   A. will   B. is going to come   C. comes    D. come

一、1. feel, have  2. will, see, has 3. are , will be  4. will dress, doesn’t work  5. lives, will keep 6. will buy, is   7. will fight, argue 8. will have, need  9. will send, tours 10. says, will feel 11. will go, doesn’t rain  12. Will, have, is   13. will write, gets  14. gets, won’t catch     15. will major, passes      

二、1. Don’t run  2. will stay, rains  3. speak, can talk with   4. will be nice 5. will be happier   6. watches, will be   7. will come, have, for  8. doesn’t rain, will, with  9. is free, will help  10. won’t, chance, doesn’t pass

三、1. will pass   2. If, take   3. Go to bed, and   4. Work hard, or   5. If, breathe, will feel

四、1. If I stay at the Four Star Hotel, I will save 40%. 2. If I stay at the Three Star Hotel, I will save 30%. 3. If I book after December 31st, it will be too late and more expensive. 4. If I want to go on the City Tour, I will have to pay 50 RMB. 5. If I want to visit the Great Wall, I will have to pay 100 RMB.

五、     1—5 CDBAD      6—10 DAACB   11—15 CBCBC